The number of large and logistically intricate research studies at Fox Chase Cancer Center (FCCC) has been steadily increasing. Many FCCC studies, including those in epidemiology, cancer control and prevention, translational research, human genetics, behavioral medicine and some animal trials employ a variety of designs that are substantially more complex than typical cancer clinical trials at FCCC. The designs of these studies often include: unique questionnaires, clinical and specimen data from large numbers of individuals (ranging from hundreds to tens of thousands);collection of longitudinal data;collection, storage and graphical display of pedigree data;online data entry and retrieval at multiple geographically distant centers;data collection using computer-aided telephone interview systems;development of specimen inventory systems;case-control and nested case-control study designs;distribution of scheduled, personalized mailings, and the collection, integration, coordination and retrieval of information generated from diverse sources and potentially stored in multiple systems. The varied populations studied in these projects and the diversity and complexity of the designs require development of study-specific computer-based tools to provide project management and coordination, and for the collection, validation, storage, and retrieval of data. The Population Studies Facility (PSF) facilitates research conducted by FCCC investigators with peer-reviewed funding by providing them access to a productive team of skilled information systems professionals. PSF personnel have substantial expertise with states-of-the-art software engineering and design as applied to cancer research. The PSF functions include development of: (a) databases for the storage and manipulation of large quantities of questionnaire, clinical, and specimen data;(b) electronic data entry and retrieval systems;(c) report generation software; (d) consistency and quality control systems;and (e) systems that provide integration and controlled exchange of data from diverse sources. The PSF developed information systems that maintain data on over 148,000 study subjects. Over the last five years, the Facility provided services to 40 investigators with peer-reviewed funding in 10 Programs from all three Divisions, representing a 38% increase over the previous funding cycle. 99% of Facility use is by investigators with peer-reviewed funding.